Fig. 3.

Antioxidant effects of methylxanthines. They protected against oxidative stress in wild type nematodes. A, in vitro evaluation of antioxidant activity using DPPH assay. B, in vivo anti-oxidant activity was detected by the quantification of intracellular ROS levels in N2 worms. C, the effect of methylxanthines on stress resistance (% survival) under a lethal dose of juglone. The experiments were carried out at least three times, ^*p < 0.05, ^**p < 0.01, ^***p < 0.001, ^****p < 0.0001, and compared to the untreated control by one-way ANOVA following Dunnett.